Incidence, Risk Factors, and Timing of Elevated Intraocular Pressure After Intravitreal Triamcinolone Acetonide Injection for Macular Edema Secondary to Retinal Vein Occlusion SCORE Study Report 15

IMPORTANCE The Standard of Care vs Corticosteroid for Retinal Vein Occlusion (SCORE) Study showed that intravitreal triamcinolone acetonide (IVTA) is effective at reducing macular edema and improving visual acuity in participants with retinal vein occlusion. Secondary analysis of the incidence, risk factors, and timing of intraocular pressure (IOP) elevation occurring after IVTA provides guidance for clinical decision making and management of patients treated with IVTA. OBJECTIVE To investigate the incidence, risk factors, and time course of IOP elevation in participants in the SCORE Study. DESIGN, SETTING, AND PARTICIPANTS Secondary analysis conducted from August through December 2014 of a prospective, randomized clinical trial featuring an evaluable population conducted at 75 clinical sites. Six hundred eighty-two patients with macular edema secondary to retinal vein occlusion were enrolled in the study. The SCORE Study enrollment period ran from November 4, 2004, to February 29, 2008, with participant follow-up ending February 28, 2009. INTERVENTIONS Study participants were randomized to standard of care, 1mg of IVTA, or 4 mg of IVTA therapy and followed up for a mean (SD) of 24.7 (10.3) months. MAIN OUTCOMES AND MEASURES Intraocular pressure elevation greater than 10 mm Hg from baseline. RESULTS Kaplan-Meier incidences of IOP elevation greater than 10 mm Hg from baseline at 36 months were 0.02 (95% CI, 0.01-0.06), 0.09 (95% CI, 0.05-0.14), and 0.45 (95% CI, 0.38-0.53) in the standard of care, 1-mg IVTA, and 4-mg IVTA groups, respectively. The rates of IOP-related events were higher for the 4-mg IVTA group compared with the other groups (P <= .001 for main outcome measure). Younger age, 4-mg IVTA vs 1-mg IVTA treatment, and higher baseline IOP were found to confer greater risk for IOP-related events (P < .05 for all). The median number of days from time of first injection to IOP elevation greater than 10 mm Hg from baseline was 34.0 and 52.5 days in participants treated with 1-mg and 4-mg IVTA, respectively. CONCLUSIONS AND RELEVANCE Intravitreal triamcinolone acetonide injection therapy, in particular the 4-mg dose, is associated with an increased risk for IOP elevation. The risk factors for an IOP-related event include higher treatment dose, younger age, and higher baseline IOP. Intraocular pressure-related events may take several months from the time of first IVTA injection to occur. Clinicians should be mindful of these risk factors when assessing the risks and benefits of IVTA therapy and also of the need for long-term follow-up of participants at risk for this complication.